In most video codecs the input video has YUV format. YUV is basically a raw uncompressed data video format which is a collection of raw pixel values in YUV color space. YUV video is composed of three components, namely one luminance (luma), i.e. Y, and two chrominance (chroma), i.e. U, V.
Considering the nature of luma and chroma components, and based on the fact that all components are presenting the same scene, there is often a high correlation between the content of different components e.g. several edges and contours are similar. However, if there is not a distinct color difference on the same object in the scene, then there is no contour present in the chroma components while there can be details and contours present on the same object in the luma component.
In conventional presentation of multiview video plus depth (MVD), each texture view is accompanied with an associated depth map. However, it may not be necessary to always use all available depth maps in the post processing steps e.g. view synthesis. This is attributed to the fact that the depth map information might be redundant and highly correlated and hence, it might be possible to create part of them from the already decoded depth maps. This will make it possible to provide the middle view depth map with a relatively lower spatial resolution targeting less bitrate and complexity while exploiting it for more efficient texture view compression.
It is known that motion vectors can be predicted or inherited from a texture picture to a depth picture or vice versa, particularly when the pictures represent the same viewpoint or camera position. However, since sufficient correlation between the sample values of the texture picture and the respective depth picture has been difficult to find, sample value prediction from a texture picture to a depth picture has not been proposed. Consequently, the compression benefit achievable from inter-component prediction (from texture to depth or vice versa) has been limited.